Replacement flow meter fits stainless steel manifolds. Flow meters allow the installer or operator to view the flow rate through each circuit. By viewing the number of gallons per minute (GPM) entering each loop of the radiant heating system, you can use the valve and flow meter to effectively balance the flow rate. It is important to balance your PEX circuit so that you can heat the floor evenly. Flow Meter Interface: G1/2 Thread Adapter: G1/2 to G3/4 Color: Red Material: Brass + Stainless Steel Package Contents: 2 x Flow Meter 2 x Adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.